PlaySudoku.us
Expert · Puzzle #591
3
7
4
5
4
6
8
3
1
2
8
2
6
9
7
6
9
1
6
9
7
2
5
The hardest published Sudoku puzzle — graded by the number of search nodes a computer needs — was named 'Al Escargot' by its creator.
The hardest published Sudoku puzzle — graded by the number of search nodes a computer needs — was named 'Al Escargot' by its creator.
"The threat is stronger than the execution." — Aaron Nimzowitsch
"The threat is stronger than the execution." — Aaron Nimzowitsch